by
Blitzer, Robert F.

Answer

$a_7=256$

Work Step by Step

The nth term of a geometric sequence can be found using the formula:
$a_n=a_1(r^{n-1})$
where
r= common ratio
$a_1$ = first term
$a_n$ = nth term
n = term number
Substitute the given values of $a_1$, n, and $r$ to find:
$a_{7}=4(2^{7-1})
\\a_{7}=4(2^6)
\\a_{7}=4(64)
\\a_{7}=256$